A High Isolation Antenna Array With Loaded Dummy for In-Band Full-Duplex Application

A high-isolation antenna array incorporating loaded dummy units (DUs) is proposed for in-band full-duplex (IBFD) applications. Through rigorous network analysis, the electromagnetic coupling between the transmitter (TX) and receiver (RX) is characterized in relation to the DU loads. Based on the network analysis, optimization of the DU loads enables effective reduction of TX-RX coupling without compromising their performances. For validation, an IBFD array with 8-port TX and RX configurations featuring ±45° dual-polarized subarrays was fabricated. The measured results agree well with the simulated results, demonstrating that the proposed array achieves isolation levels exceeding 60 dB across the 4.8–4.9 GHz operational bandwidth. It indicates that the proposed array is a promising candidate for IBFD applications.